340 X heads

Depends on what has to be done and what your using them for. With the cost of machine work and the price of Guides , Valves, Springs, retaners , and all hardwear sometimes its cost effective to buy New aluminum heads. If you need them for a numbers restore thats a different story.

All X heads or castings ending with 894 I pulled from original blocks that were that were casted in 67 - 68. These were for 68 - 69 cars. All 70 cars I dismantled Had U or Z casting ending in 915. Alot of guys call these J heads . I believe the spark plug hole surface milling cuts off the U .

I know there were probably early motors in 70 cars. but not many, I myself never saw a X head on a 69 dated block and I had alot of them.